diff --git a/iocsh/sis8300llrf.iocsh b/iocsh/sis8300llrf.iocsh
index 00d47ef47d07002df5cb840f38efda572611bc37..0dc84a0c15b9267ccf2250247994f8c7d5a2d215 100644
--- a/iocsh/sis8300llrf.iocsh
+++ b/iocsh/sis8300llrf.iocsh
@@ -4,8 +4,8 @@
 #######################
 epicsEnvSet("LLRF_NOPULSETYPES" "$(SIS8300LLRF_NOPULSETYPES=1)")
 
-epicsEnvSet("SP_SMNM_MAX"              "0xFFFFFF")
-epicsEnvSet("FF_SMNM_MAX"              "0xFFFFFF")
+epicsEnvSet("SP_SMNM_MAX"              "0xC350")
+epicsEnvSet("FF_SMNM_MAX"              "0xC350")
 epicsEnvSet("PIERR_SMNM_MAX"           "0x10000")
 epicsEnvSet("AI_SMNM_MAX"              "0x200000")       
 epicsEnvSet("CAL_SMNM_MAX"              "1000")